Regeneration and CO2 Recovery System for Closed Loop Blood Oxygenator

BACKGROUND

1. Field

The present disclosure relates to oxygenators, and particularly to a regeneration and CO 2 recovery system for oxygenators.

2. Description of the Related Art

For patients with life-threatening heart/lung diseases, deoxygenated blood can be oxygenated by an oxygenator. However, in conventional open loop oxygenators, 70% of medical O 2 is wasted without being used.

SUMMARY

Open-loop blood oxygenators have very low efficiency in terms of O 2 usage. A closed-loop blood oxygenator includes a regenerator that minimizes the amount of O 2 needed and reduce long term costs.

The regenerator receives gas from the oxygenator. The gas flows through a cylinder containing activated carbon (AC) to filter CO 2 from the gas. The left over O 2 is reused and cycled back to the oxygenator through the cylinder. To keep the level of CO 2 within an acceptable range inside the system, the AC is thermally regenerated thereby releasing the CO 2 which is then stored.

The closed loop blood oxygenator includes a built-in thermal regenerator used on a saturated adsorbent within the cylinder. Released CO 2 is stored and the efficiency of the system is increased by reusing unused O 2 . This system is more eco-friendly because it captures released CO 2 and generates profit by selling the stored CO 2 .

A regeneration and CO 2 recovery system for a closed loop blood oxygenator, in one embodiment, includes a rotary cylinder having an input, a first output and a second output. A plurality of columns are located within the rotary cylinder. The input flows through a first column of the plurality of columns to the first output. A CO 2 adsorbent is located in each of the plurality of columns. A heater is located adjacent a second column of the plurality of columns. The second column allows gas flow to the second output. The rotary cylinder rotates the first column to the second output when adsorbent in the first column is saturated and the heater heats the first column to release the CO 2 through the second output.

A sensor, such as a CO 2 sensor, can be used to determine when the adsorbent in the first column is saturated.

An oxygenator, in some embodiments, is connected to the input and the first output.

An O 2 supply is connected to the first output through a valve. A control unit maintains the oxygen level at 200 mmHg.

A vacuum pump is connected to the second output and moves released CO 2 into a storage tank connected to the second output.

The adsorbent can be an MOFs or a KOH-Modified AC.

A regeneration and CO 2 recovery method for a closed loop blood oxygenator includes receiving gas through an input to a first column of a rotary cylinder having a first output and a second output; adsorbing CO 2 through an adsorbent located in the first column and allowing O 2 to pass through the first column to the first output; exhausting O 2 through the first output; rotating the first column to the second output when the adsorbent is fully saturated with CO 2 ; heating the first column at the second output with a heater located adjacent to the second output; and releasing CO 2 from the first column to the second output.

The method further includes using a sensor to determine when the adsorbent in the first column is saturated.

The method further includes supplying O 2 to an oxygenator through the first output and receiving gas from the oxygenator through the input.

O 2 is supplied from an O 2 supply connected to the first output through a valve.

The oxygen level is maintained at 200 mmHg using a control unit.

The released CO 2 is moved into a storage tank connected to the second output using a vacuum pump.

These and other features of the present subject matter will become readily apparent upon further review of the following specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram illustrating the process of a closed-loop blood oxygenator regeneration and CO 2 recovery system.

FIG. 2 is an illustration of a closed-loop blood oxygenator regeneration and CO 2 recovery system.

FIG. 3 A is an illustration of a vacuum pump and storage container.

FIG. 3 B is an inner view of a rotary cylinder.

FIG. 3 C is a top view of the inside of the rotary cylinder.

FIG. 3 D is a perspective view of the closed-loop blood oxygenator regeneration and CO 2 recovery system.

FIG. 4 is a table of adsorbent materials showing an evaluation of their properties.

Similar reference characters denote corresponding features consistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A high-efficiency closed-loop blood oxygenator includes a regenerator designed with columns using activated carbon (AC) as a CO 2 adsorbent. The AC is thermally regenerated, thereby releasing the CO 2 which is then stored and sold. Storing CO 2 helps to reduce greenhouse effects and, in some embodiments, it is expected that around SR 30-45 worth of CO 2 can be stored per hour, making this an eco-friendly and profitable design. Unused O 2 can then be reused.

Overall, the amount of O 2 needed is reduced since the system reuses unused O 2 , operating costs in the long term are reduced, and the environment is protected by storing released CO 2 .

FIG. 1 is a flow diagram illustrating the process of a closed-loop blood oxygenator regeneration and CO 2 recovery system. O 2 is supplied to the system through a valve controlled by a control unit (i.e. electronic control unit) to maintain an oxygen level of 200 mmHg. Gas exchange occurs between blood and gas through a membrane by diffusion due to a concentration gradient. CO 2 in the system is adsorbed by an adsorbent until the adsorbent is saturated (6 mmHg in some embodiments). A CO 2 sensor can be used to determine when the adsorbent is fully saturated, and when it is determined that the adsorbent is fully saturated, the adsorbent is thermally regenerated. In some embodiments, a heating element is used to heat the adsorbent to around 60 degrees C., releasing the CO 2 from the adsorbent. The released CO 2 is then captured and stored. A vacuum pump can be used to capture and move the released CO 2 into a storage tank.

FIG. 2 is an illustration of a closed-loop blood oxygenator regeneration and CO 2 recovery system 100 . A rotary cylinder 105 has an input 110 , a first output 115 and a second output 120 . A plurality of columns 125 are located within the rotary cylinder 105 . The input 110 flows through a first column 125 ( 1 ) of the plurality of columns to the first output 115 . A CO 2 adsorbent 130 is located in each of the plurality of columns 125 . A heater 135 is located adjacent a second column 125 ( 2 ) of the plurality of columns 125 . Gas from the second column 125 ( 2 ) flows to the second output 120 . The rotary cylinder 105 rotates the first column 125 ( 1 ) to the second output 120 when adsorbent in the first column 125 ( 1 ) is saturated. The heater 135 heats the first column 125 ( 1 ) to release CO 2 through the second output 120 . A vacuum pump 140 is connected to the second output 120 and moves the released CO 2 into a storage container 145 .

The cycle continues until the adsorbent 130 is fully saturated, and CO 2 will not be further adsorbed by the adsorbent 130 . A CO 2 sensor detects the level of CO 2 in the gas or adsorbent. When the CO 2 level reaches 6 mmHg, the column switches. A new column with fresh adsorbent allows adsorption to continue.

The saturated adsorbent 130 is then thermally regenerated. When the adsorbent 130 is heated by the heater 135 (e.g. heating element) to around 60° C., CO 2 is released. The vacuum pump 140 moves CO 2 and stores it in the storage container 145 (storage tank). To prevent leakage of CO 2 during transfer to the tank, it has a valve at its opening. This valve is closed during the rotation of the column. Once the columns stop moving, the valve opens to allow CO 2 to move from the column to the tank during the regeneration process.

An oxygenator 150 is connected to the input 110 and the first output 115 .

An O 2 supply 155 is connected to the first output 115 through a valve 160 .

Gas exchange occurs between blood and gas through a membrane by diffusion. CO 2 and O 2 flow through a pipe 160 and enter the rotatory cylinder 105 that contains our adsorbent 130 . CO 2 is adsorbed by the adsorbent 130 and O 2 is reused by flowing through first output 115 back to the oxygenator 150 .

FIG. 3 A is an illustration of the vacuum pump 140 and storage container 145 . FIG. 3 B is an inner view of the rotary cylinder 105 and FIG. 3 C is a top view of the inside of the rotary cylinder 105 . FIG. 3 D is a perspective view of the closed-loop blood oxygenator regeneration and CO 2 recovery system 100 .

FIG. 4 is a table of adsorbent materials showing an evaluation of their properties. Although using soda lime is the most popular CO 2 absorbent, it has many drawbacks. For example, to signal the saturation of soda lime indicators are used. It is suspected that these indicators release harmful compounds. In addition, soda lime dust inhalation also causes airway diseases. Therefore, it is suggested to use other materials to remove CO 2 , although soda lime could be used.

Temperature swing adsorption is chosen because it can be done using heating element that heats up to 60° C. The regenerated adsorbent can be reused many times. During the process of regeneration, CO 2 is absorbed by the adsorbent.

One option is to use metal-organic frameworks (MOFs) that have much higher adsorption capacity and is also regeneratable. MOFs are, however, very expensive and not always readily available. KOH-Modified AC is the next best option due to low cost and high availability (can be locally prepared from agricultural waste such as date seeds, which is currently done at the center of research center at King Faisal University in Saudi Arabia).

It is to be understood that the present invention is not limited to the specific embodiments described above, but encompasses any and all embodiments within the scope of the generic language of the following claims enabled by the embodiments described herein, or otherwise shown in the drawings or described above in terms sufficient to enable one of ordinary skill in the art to make and use the claimed subject matter.